MGMT and glioblastoma: Two ongoing phase III trials are investigating nivolumab for the treatment of newly diagnosed GBM: The CheckMate-548 trial is testing temozolomide plus radiotherapy combined with nivolumab or placebo in patients with newly diagnosed MGMT-methylated GBM (NCT02667587), and the CheckMate-548 trial is investigating nivolumab versus temozolomide, in combination with radiotherapy, in patients with newly diagnosed MGMT unmethylated GBM (NCT02617589).